Pieris marginalis
Margined White

Family Description:
This species is considered a variety of Artogeia napi by some sources.
The caterpillar is dark green and striped lengthwise along the back and sides with yellow.
Adult: This butterfly is medium-sized, with a wingspan ranging from 1 to 2 inches. It varies in its appearance depending on when it emerges. Spring butterflies are white on the upperside, with the tip of the forewing marked with black. Underneath is white except for the tip of the forewing and the entire hindwing, both of which are marked with yellowish to grayish green on the veins. Summer butterflies are entirely white both on the upper- and undersides.

This species ranges from southern British Columbia and Alberta south to California, Arizona, and New Mexico; it extends east as far as Wyoming and Colorado. It occurs through most of Idaho.


It can be found in meadows, forests, and woodlands.


Caterpillar: Caterpillars feed on the leaves of native species in the mustard family (Brassicaceae).
Adult: Butterflies drink flower nectar, often from host plants.


There are two generations of caterpillars each year. Caterpillars of the second generation pupate, then overwinter within their chrysalises in a physiological state called diapause. Adults generally fly from May through August in most of its range.


Males actively patrol in search of receptive females. Females lay eggs singly on the undersides of leaves of host plants.

Idaho Status: Unprotected nongame species.
Global Rank:

G5; populations are widespread, abundant, and secure.

Ferris, C. D. and F. M. Brown. (eds.) 1981. Butterflies of the Rocky Mountain States. Univ. of Oklahoma Press, Norman, Oklahoma, USA, 442 pp.

Opler, P. A., H. Pavulaan, and R. E. Stanford. 1995. Butterflies of North America. Jamestown, North Dakota, USA: Northern Prairie Wildlife Research Center Home Page. http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/bflyusa.htm (Version 05Nov98).

Opler, P. A. and A. B.Wright. 1999. A Field Guide to the Western Butterflies. Second Edition. Peterson Field Guide Series. Houghton Mifflin Company, New York, New York, USA, 540 pp.

Pyle, R. M. 1981. National Audubon Society Field Guide to North American Butterflies. Alfred A. Knopf, Inc., New York, New York, USA, 924 pp.

Stanford, R. E. and P. A. Opler. 1993. Atlas of Western U.S.A. Butterflies (Including Adjacent Parts of Canada and Mexico). Published by authors, Denver, Colorado, USA, 275 pp.